Height limiter



April 1; 1969 V G. OMON HEIGHT LIMITER She et Filed May 1, 196 7 INVENTOR. GENE L. OMON' WIL'S ON, 3ETTLE, BATCHELDER G. 1.. OMON HEIGHT LIMITERQ April 1; 1969 Sheet Filed May i, 1967 INVENTOR.

WILSON, SETTLE, BATCHELDER ATT'YS aplgma '7 April 1, GI OM QN" SHEIGH'I LI ITER shes; "5 of 5 f f Filed May 1, 1967 INVENTOR. 'GEWE L. OMON BY WILSON, SET n. E, BATCHELDER United States Patent Ofice,

3,435,974 Patented Apr. 1, 1969 3,435,974 HEIGHT LIMITER Gene L. Omon, Wauwautosa, Wis., assignor to J. I. Case Company, Racine, Wis., a corporation of Wisconsin Filed May 1, 1967, Ser. No. 635,147 Int. Cl. E02f 3/00 US. Cl. 214-762 13 Claims ABSTRACT OF THE DISCLOSURE A vehicle having boom means pivotally mounted on the vehicle to move an implement between raised and lowered positions through a fluid motor with valve means selectively supplying the fluid to the motor. Indexing means are provided for maintaining the valve in the operated position and the indexing means are actuated in response to predetermined pivotal movement of the boom arms on the vehicle to allow the valve to close thereby positioning the boom arms relative to the vehicle.

Background of the invention The present invention relates generally to material handling equipment and more particularly to means for automatically neutralizing the actuating means of an implement on a vehicle when the implement has reached a predetermined position on the vehicle.

In conventional earth moving equipment, such as bucket loaders, the machine generally includes one or more lift arms pivotally carried on a vehicle, such as a tractor, with a bucket pivotally mounted on the free end of the lift arms. The lift arms are generally moved between raised and lowered positions by actuating means including a fluid motor and a valve which selectively supplies fluid to the motor.

One of the most common uses for a bucket loader is the filling of a truck or other type of vehicle. In this type of operation, the operator must continuously maneuver the loader between the pile of material and the truck and during this maneuvering the operator must simultaneously raise the boom to elevate the bucket so as to clear the top of the truck. After the contents of the bucket have been dumped, the operator must maneuver the loader to return to the pile of material and at the same time lower and position the bucket to the digging position.

While the vehicle is being maneuvered between the pile and the truck, all of the attention of the operator must be directed to steering the vehicle and controlling the direction of movement of the vehicle. Thus, the bucket must be raised to the dumping position either before or after the vehicle has been maneuvered between the pile of material and the truck.

of course, the time required to complete this type of operation has a direct bearing on the cost and thus decreasing the cycling time for performing this operation by a matter of a second will greatly reduce the cost.

Various types of controls have been proposed for automatically limiting or positioning the boom arms in the raised position on the vehicle. However, so far as applicant is aware, all of these devices require complicated mechanisms including a mechanical or link-age connection between the movable lift arms and the fixed control valve carried by the vehicle.

Summary of the invention Generally speaking, the present invention includes indexing means for locking the control valve in an operated position thereby directing fluid to the motor to raise the lift arms and bucket. Electrical means are provided for releasing the indexing means which includes a switch that is actuated by a member rotated in response to predetermined movement of the lift or boom arms on the vehicle.

A primary object of the present invention is to provide means for automatically limiting the height of the boom of a vehicle without a direct connection between the control elements on the vehicle and on the boom.

Another object is to provide a simplified connection between the hydraulic actuating means and the vehicle which automatically controls the positioning of the actuating means.

Other objects and features of the invention will become apparent when considered in conjunction with the following specification and the accompanying drawings.

As shown in the drawings:

FIGURE 1 is a side elevation of a vehicle mounted implement or loader embodying the present invention;

FIGURE 2 is a vertical sectional view taken generally along line 2-2 of FIGURE 1;

FIGURE 3 is a fragmentary elevational view of the details shown in FIGURE 2;

FIGURE 4 is a schematic illustration of the electrical circuitry;

FIGURE 5 is an enlarged sectional view of the control valve;

FIGURE 6 is a sectional view similar to FIGURE 3 showing a modified form of the invention;

FIGURE 7 is a sectional view taken along 7-7 of FIGURE 6;

FIGURE 8 is a vertical sectional line 88 of FIGURE 7;

FIGURE 9 is a fragmentary sectional view of the lift arm showing a slightly modified form of the invention shown in FIGURE 1; and

FIGURE 10 is an end view of the lift arm shown in FIGURE 9.

In the specification:

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of the parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and application and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for purpose of description and not of limitation.

Referring to FIGURE 1 of the drawings, there is shown a vehicle loader, which is generally indicated by the numeral 10. The vehicle loader 10 includes forward and rearward articulated sections 12 and 14 which are supported on front and rear wheels 16 and 1 8, only one of each wheels being visible in FIGURE 1. The vehicle 10 also includes an operator station generally indicated by the numeral 20.

The vehicle 10 includes boom means which are illustratively shown as a pair of boom or lift arms 22, only one of which is visible in FIGURE 1. It will be understood that there is another boom arm on the opposite side of the machine and each boom arm has its rear end pivotally mounted at 24 on the forward section 14 of the vehicle. The forward ends of the boom arms pivotally support a bucket 26- which is moved on the arms 22 through pivotally interconnected links 28, 30, and a fluid motor 32 having one end connected to the link 30 and the opposite end connected to the forward section 12 of the vehicle. Fluid is selectively admitted to opposite ends of the motor 32 from a control valve and conduit means (not shown).

The boom means or lift arms 22 are adapted to be pivoted between raised and lowered positions on the vehicle through hydraulic actuators or fluid motors 40 interconnecting the boom arms 22 and the vehicle section 12. Fluid is selectively admitted to opposite ends view taken along of the motor 40 through conduits (not shown) by a control valve 42 having a valve spool 44, which is normally maintained in the neutral position by self-restoring means 46. During normal operation, the valve spool is moved between neutral and operated positions by a control lever 48 disposed in the operators compartment of the vehicle and pivotally interconnected with the free end of the spool 44.

According to the invention, means are provided for controlling the fluid valve and motor which will automatically neutralize the motor, stopping the pivotal movement of the boom arms on the vehicle to define the raised position of the boom arms on the vehicle. This is accomplished by providing indexing means for locking the valve in an operated position and an electrical circuit having a switch adjacent the boom arms which is actuated in response to movement of the boom arms on the vehicle to complete the electrical circuit and allow the valve to return to the neutral position.

In the illustrated embodiment, the indexing means includes a housing 50 carried adjacent the end of the control valve 42 with a valve spool extension 52 slidably disposed in the housing 50. The extension 52 includes an enlarged portion 54 which defines a shoulder 56. The housing 50 also supports detent means or balls 58 slidable in openings therein and adapted to lock the valve spool in an operated position whereby fluid is being directed to the hydraulic motor 40 to raise the boom arms on the vehicle.

The detent means 8 are normally maintained in engagement with the shoulder 56 formed on the valve spool extension 52 by a detent holder 60 that is spring biased to an operated or locked position 'by a spring 62. The holder 60 is adapted to be moved between the locked position and a release position by a plunger 64 fixedly secured to the detent holder 60. The plunger is adapted to be moved between two positions by an electrically actuated solenoid 66 surrounding the plunger and which, when energized, moves the plunger from the position shown in FIGURE 5 inthe direction of the arrow A to release the detent means 58 and allow the self-restoring means 46 to move the valve to the neutral position.

The electrical circuit means for the solenoid 66, forming part of the indexing means, includes a first wire 70 operatively connected to the ignition switch 72 of the vehicle 10. A second wire 74 has one end connected to the solenoid 66 and the opposite end connected to a first terminal of a normally open switch 76. The second terminal of the normally open switch 76 is connected through a wire 78 to a second switch 82 which, in turn, is grounded through a wire 81 connected to the vehicle proper.

In the illustrated embodiment of FIGURES 2 and 3, the means for actuating the second switch 82 includes a member or shaft 90 rotatably supported in a. tubular member 92 fixedly secured to a plate 94 forming a part of the articulated section 12 of the vehicle 10. One end of the shaft 90 has a plate 96 fixedly secured thereto with the switch 82 mounted on the plate 96 by screws. The plate 96 has a recess or opening 98 which receives a pin 100 carried by a second plate 102 rotatably supported on the hollow shaft 92 and adapted to be moved to a plurality of positions by a control rod 104 disposed in the operators compartment of the vehicle. The shaft 90 is biased to a first position by a tension spring 105 having opposite ends respectively carried by the plate 96 and the pin 100 so that the actuating member 107 of switch 82 is spaced from the pin or stop 100. A suitable cover plate 106 may be provided for partially enclosing the switch 82 and various other elements of the actuating means.

The opposite end of the shaft 90 has an arm 110 removably secured thereto by a set screw 112. A second arm or pin 114 is fixedly secured to one of the boom arms 22 and the arm 110 and pin 114 form first and second abutment means, for a purpose to be described later.

The operation of the embodiment shown in FIGURES 1 through 5 can readily be appreciated from the following description. The control lever 48 disposed in the operators compartment of the vehicle, is rotated counterclockwise to move the valve spool 44 to an actuated position thereby placing the detent means 58 in contact with the shoulder 56 formed on the valve spool extension 52. The action of the spring 62 will lock the detent means 58 against the shoulder 56 to maintain the valve spool in the operated position. As the valve control lever is rotated counterclockwise the actuating finger 77 of the normally open switch 76 is engaged by a pin carried by the linkage between the valve control lever and the valve spool to close the switch 76. In this position fluid is directed from the valve to the fluid motor 40 to pivotally move the boom arms from the lowered position towards the raised position.

As the boom arms approach a predetermined raised position, the pin 114, forming an abutment on the boom arm, engages the abutment formed by the extension or arm 110 which causes the shaft to rotate clockwise as viewed in FIGURE 3. Rotation of the shaft 90 will carry the actuating member 107 of switch 82 into contact with the stop as shown in FIGURE 3 thereby actuating the switch and completing the circuit to the solenoid 66. Energizing the solenoid 66 will move the plunger 64 leftward as viewed in FIGURE 5 to overcome the action of the spring 62 allowing the self-restoring means 46 of the valve spool 44 to force the detent means 58 into the opening in the detent holder and move the valve spool to the neutral position. Of course, movement of the valve spool to the neutral position will neutralize the fluid motor 40 and stop pivotal movement of the lift arms and the bucket on the vehicle.

As clearly shown in FIGURE 3, rotation of the plate 102 carrying the pin or stop 100 may be accomplished by the operator from the operators compartment of the vehicle by merely moving the control rod 104 in the appropriate direction. The spring biasing the switch and shaft 90 to the first position will rotate the shaft 90 in the tubular member or hollow tube 92 to reposition the abutment 110 carried on the end of the shaft. Thus, moving the control rod 104 in the appropriate direction will result in changing the raised stopping position of the boom arms on the vehicle.

Of course, it will readily be appreciated that this repositioning of the boom arm on the vehicle may be accomplished by moving the pin or second abutment 114 carried by the lift arm 22 or by repositioning the first abutment or arm 110 on the shaft 90.

A slightly modified form of the invention is disclosed in FIGURES 6 through 8, wherein like reference numerals will be used to designate identical parts of the embodiment shown in FIGURES 1 through 5. As shown in FIGURE 7, a shaft is rotatably journaled in a support 122 carried by the frame part 94 forming a part of the vehicle section 12. One end of the shaft 120 has a finger or arm 124 fixedly secured thereto by a set screw 126 with the finger 124 forming a first abutment adapted to be engaged by the pin or abutment 114 carried by the lift arm 22.

The shaft 120 is provided with a plate 130 fixedly secured thereto to rotate therewith. The plate or member 130 has a pin 132 secured thereto which acts as a stop for actuating a switch 134. The switch 134, which is identical in function as that of switch 82 shown in the embodiment illustrated in FIGURES 1 through 5, is supported on an arm 136 fixedly secured to a hollow shaft 138 that is rotatably journaled on the shaft 120.

A positioning lever 140 is rotatably journaled on a bolt 142 threadedly received in a lug 144 secured to the frame part 94 and disposed in the operators compartment of the vehicle, A first arm 146 is carried by the control lever 140 to rotate therewith and the arm 146 is pivotally connected at 148 to an adjustable link 150. The

opposite end of the link 150 has an elongated slot 152 which receives a bolt 154 threadedly received in an opening of a crank 156 keyed to the hollow shaft 138.

The shaft 120 and pin or stop 132 are normally urged to a first position by a spring 160 having one end secured to the plate 130 and the opposite end secured to the support 122. Also, as shown in FIGURE 8, hollow shaft 138, arm 136 and crank 156 are normally urged to a first position, wherein the actuating member of the switch 134 is depressed, by a spring 162 having one end connected to the arm 136 and the opposite end connected to the support 122. Thus, in normal operation the crank 156, bolt 154 and switch 134 are urged in a clockwise direction, as viewed in FIGURE 6, to move the bolt 154 in the slot 152 to a position shown in FIGURE 6 and have the actuating member of the switch 134 spaced from the stop 132. However, counterclockwise rotation of the member 130 and stop 132 depress the switch 134 and continued counterclockwise rotation of the plate 130 will carry the plate 136 against the action of the tension spring 160 to move the bolt 154 within the slot 152. Thus, the slot 152 in the link 150 will result in a lost motion connection between the control lever 140 and the limit switch 134 to allow the switch to move relative to the lever 140 and control linkage 150. Preferably, an adjustable stop 170 is carried by the plate 136 to engage the plate 130 during this action to eliminate damage to the switch 134.

The operation of the modified form of the invention, shown in FIGURES 6 through 8, is similar to that disclosed and described in the embodiment shown in FIG- URES 1 through 5 and the electrical circuitry is identical to that shown in FIGURE 4. Thus, a predetermined rotation of the lift arm 22 will force the abutment 114 into contact with the abutment 124 thereby rotating the shaft 120 counterclockwise forcing the stop 132 into contact with the switch 134 which will actuate the switch. Actuation of the switch 134 of course will complete the circuit to the solenoid 66 and allow the valve spool 44 to move to the neutral position.

The height or raised position of the lift arms on the vehicle in the modified form of the invention can readily 'be adjusted by rotation of the lever 140 in the appropriate direction. Thus, if the maximum raised position is to be increased, the lever 140 is rotated clockwise and the hollow shaft 138 carrying the switch 134 will be rotated counterclockwise against the bias of the tension spring 162 to move the switch away from the stop 132 increasing the rotational travel of the lift arms before the switch is actuated. Likewise, counterclockwise rotation of the lever 140 will cause the spring 162 to rotate the arms 156 and 136 and shaft 138 carrying switch 134 clockwise to decrease the distance between the stop 132 and the switch 134. This will decrease the amount of pivotal movement of the lift arms before the stop 132 will actuate switch 134.

A further modification is shown in FIGURES 9 and 10. The modification disclosed in FIGURES 9 and 10 can readily be incorporated in either of the embodiments disclosed herein above. Thus, the raised position of the lift arms on the vehicle can be varied by moving a pin or abutment, equivalent to abutment 114, relative to the lift arm 22 to vary the height limit of the lift arms. In the illustrated embodiment, this is accomplished by providing a pair of sleeves 200 rotatably supported on the pivot point 24 for the lift arm 22. Each sleeve 200 is provided with a block 202 having an opening 204 therein. The opening slidably receives a lug or pin 206 which is urged by a spring 210 into any one of a plurality of recesses 208 formed on the arm 22. The spring is telescoped over the rod portion of a handle 212 with one end in constant engagement with the pin 206 and the opposite end in engagement with a removable plate 214 secured to the blocks 202.

Thus, by pulling the handle 212, the pin 206 may be moved against the action of the spring 210 and repositioned into any one of the plurality of recesses 208 to readily change the maximum raised position of the lift arms relative to the vehicle.

Of course, if desired, the abutments 124 or could readily be moved with respect to the shafts or 90, respectively, to change the position of engagement of the abutment on the shaft and on the lift arm. Furthermore, the second switch 82 or 134 could be disposed directly in the path of the pin or abutment 114 to be engaged by the abutment upon predetermined pivotal movement of the lift arm 22.

While several preferred embodiments of the invention have been shown and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention as defined by the following claims.

I claim:

1. In a vehicle having a boom arm pivotally mounted thereon and fluid means for raising said boom arm, said fluid means including a fluid motor and a control valve with a spool slidable between operated and self-restoring neutral positions for selectively supplying fluid to said motor, the improvement comprising means for automatically positioning said boom arm on said vehicle including a member movably supported on said vehicle, indexing means carried by said valve for maintaining said valve in operated position, electric circuit means connected to said indexing means and having a switch associated with said member, and first and second abutment means respectively secured to said member and said boom arm with said abutment means normally spaced from each other, said abutment means adapted to engage each other upon predetermined movement of said arm for actuating said switch to complete said circuit releasing the indexing means to allow said valve to return to neutral and stop said boom arm on said vehicle in a predetermined position.

2. A vehicle as defined in claim 1, including the further improvement of a stop adjacent said member adapted to control and actuate said switch and adjustment means for changing the contact position of said switch and stop to change the predetermined stopping position of the arm on the vehicle.

3. A vehicle as defined in claim 2, in which said adjustment means includes a rod connected to said stop to move said stop relative to said switch.

4. A vehicle as defined in claim 2, in which said adjustment means includes a control lever movable on said vehicle, linkage means operatively connecting the lever to the switch whereby movement of said lever will move said switch relative to said stop.

5. A vehicle as defined in claim 1, including the further improvement of adjustment means for moving second abutment between spaced points on said boom arm and means for locking said second abutment at each of said points.

6. A vehicle as defined in claim 1, including the further improvement of means for rotating said member and first abutment on said vehicle to a plurality of adjusted positions.

7. A vehicle as defined in claim 1, in which said circuit means includes a second switch adjacent said valve and actuating means for closing said second switch when said valve spool is moved to an operated position and opening said switch when the spool is moved to neutral position whereby said circuit is completed while said spool moves between operated and neutral positions.

8. A vehicle as defined in claim 1, in which said memher and switch are rotatably supported on said vehicle, and said last means includes a stop disposed in the path of said switch, means for producing relative movement between said switch and stop in response to movement of said boom on said vehicle to actuate said switch.

9. In a vehicle having boom means pivotally mounted thereon for movement between raised and lowered positions, hydraulic means including a fluid motor for raising and lowering said boom means and a valve movable between operated and self-restoring neutral positions for selectively directing pressured fluid to said motor, the improvement comprising means for controlling said hydraulic means including indexing means carried by said valve :for locking said valve in an operated position to raise said boom means, releasing means connected to said indexing means and including circuit means, a movable member supported on said vehicle, a switch in said circuit means and movable with said member, and means responsive to pivotal movement of said boom means for moving said member thereby closing said switch and completing said circuit means to allow said valve to close and stop the movement of said boom means, said last means including a stop disposed in the path of said switch and means for moving the stop to a plurality of positions to define raised positions of said boom means on said vehicle.

10. In a vehicle having boom means pivotally mounted thereon for movement between raised and lowered positions, hydraulic means including a fluid motor for raising and lowering said boom means and a valve movable between operated and self-restoring neutral positions for selectively directing pressured fluid to said motor, the improvement comprising means for controlling said hydraulic means including indexing means carried by said valve for locking said valve in an operated position to raise said boom means, releasing means connected to said indexing means and including circuit means, a member rotatable on said vehicle, a switch in said circuit means rotatably supported by said member, means resiliently urging said member and switch to a first position, a first abutment rotatable with said member, a second abutment rotatable with said boom means and engaging said first abutment upon predetermined pivotal movement of said boo-m means to rotate said member and switch to a second position causing said switch to be actuated to close said circuit means to said indexing means.

11. A vehicle as defined in claim 10, further including means for moving said switch relative to said member which includes a lever, a linkage having a lost-motion connection connecting the lever to the switch whereby movement of the lever will reposition the switch to change the predetermined raised position of said boom means.

12. In a vehicle having boom means pivotally mounted thereon for movement between raised and lowered positions, hydraulic means including a fluid motor for raising and lowering said boom means and a valve movable between operated and self-restoring neutral positions for selectively directing pressured fluid to said motor, the improvement comprising means for controlling said hydraulic means including indexing means carried by said valve for locking said valve in an operated position to raise said boom means, releasing means connected to said indexing means and including circuit means, a movable member rotatably supported on said vehicle, a switch in said circuit means carried by said member, a stop fixed to said member, means urging said member and stop to a first position and abutment means on said member and said boom means to rotate said stop and member in response to predetermined pivotal movement of said boom means causing said switch to be actuated to close said switch and stop the movement of said boom means.

13. In a vehicle having boom means pivotally mounted thereon for movement between raised and lowered positions, hydraulic means including a fluid motor for raising and lowering said boom means and a valve movable between operated and self-restoring neutral positions for selectively directing pressured fluid to said motor, the improvement comprising means for controlling said bydraulic means including indexing means carried by said valve for locking said valve in an operated position to raise said boom means, releasing means connected to said indexing means and including circuit means, a movable member supported on said vehicle, a switch in said circuit means and movable with said member, and means responsive to pivotal movement of said boom means for moving said member thereby closing said switch and completing said circuit means to allow said valve to close and stop the movement of said boom means, said last means including a pin carried by said boom means and rotatable therewith, an abutment on said member and disposed in the path of said pin, means movably urging said member to a first position and movable to a second position, whereby movement of said boom means will move said pin into contact with said abutment to move said member to the second position and close said switch.

References Cited UNITED STATES PATENTS 3,141,562 7/1964 McAdams 2l4--762 3,187,913 6/1965 Strader et al 2-l4-7 64 X 3,198,360 8/1'965 Strader et al 214--764 HUGO O. SCHULTZ, Primary Examiner. 

